Method of receiving electrical oscillations



Patented Dec. 30, 1924..

UNITED s1 res ALEXANDER MEISSNER, o'E BERLIN, GERMANY, ASSIGNOR ToGESELLSCHAFT E'tiR DRAI-ITLOSE TELEGRAPHIE M. B. H., or BERLIN, GERMANY,A CORPORATION OF GERMANY.

I METHOD or RECEIVING ELECTRICAL osoinna'r roNs.

17o Drawing Application filed September 3, 1921. Serial No. 498,414.

(GRANTED UNDER THE rn'ovr's r'o s' or THE ACT OF NAME 3, 1921, 41 STAT.L., 1313.

To all whom it may concern:-

B'e itknown that I, ALExnNnER MmssN-En, citizen of the German Republic,residing atBerlin, Germany, have invented certain new and usefulImprovements in Methods of Receiving Electrical Oscillations, for whichI have filed applications as follows: Germany, Patent No. 285,279, filedOct. 14, 1913; Argentina, Patent No. 11,269, filed Feb. 27, 1914;Australia, Patent No. 34,487, filed Feb. 17, 1914; Belgium, Patent No.263,703, filed J an. 12, 1914; Brazil, Patent No. 8,241, filed Apr. 15,1914; Chile, Patent No. 3,094; Denmark, Patent No. 21,068, filed Dec. 4,1914; England, Patent No. 252/14, filed Jan. 5, 1914; France, Patent No.467,747, filed J an. 27, 1914; Holland, Patent No. 3,267, filed Jan. 22,1914; Italy, Patent No. 422/242, filed Jan. 12, 1914; Mexico, Patent No.15,059, filed Apr. 14, 1914; New Zealand, application No. 34,487, filedFeb. 28, 1914; Austria, Patent No. 79,829, filed Jan. 7, 1914; Peru,filed March 19, 1914; Rumania, Patent No. 3,761, filed March 18, 1914;Sweden, Patent No. 40,257, filed Feb. 4, 1914; Spain, Patent No. 57,310;Turkey, Patent No. 2,298, filed Feb. 26, 1914; Hungary, application No.112,383, filed J an. 29, 1914; Tschechien, Patent No. 4,097, filed Jan.2, 1920, of which the following is a specification.

As is well known, there are wireless telegraph receiving arrangementsoperable 1n a manner such that through the mutual ef fect of theoscillations received and auxiliary oscillations produced at thereceiving station and having a frequency differing slightly from thereceived frequency, vibrations will be generated which will producemusical sounds.

The present invention relates to a method of receiving radio energy inaccordance with which the frequency of the auxiliary oscillations doesnot lie near to the fundamental frequency of the received oscillations,but, on the contrary, is differentiated from a multiple or aliquot partof the fundamental frequency of the energy to be received. It has beenfound that musical sounds will be produced whenever the frequency of theauxiliary oscillations differs by an audio frequency from a multiple oraliquot part of the oscillation to be received. I

Under certain conditions, the use of auxiliary oscillations having afrequency approaching a multiple or aliquot part of the fundamentalfrequency of the received 0scillations, as the case may be, has severaltechnical advantages over the use of nearly equal auxiliary and receivedfrequencies. Of such advantages, the following may be mentioned lVhenarc lamp generators are used for producing auxiliary oscillations at thereceiving station for heterodyning the oscillations being received, itis preferable to give the auxiliary oscillations a frequency which ismaterially smaller than the frequency of the received energy, becausethe greater the wave length, the less theeffect of irregularities in theoscillations generated by the arc lamp. Accordingly, the lower thefrequency of the arc lamp generator, the clearer are the soundsobtained.

If it isdesired to receive damped oscillations produced by a sparksender, the fre quency of the oscillations produced at the receivingstation being lower than or approximately equal to the fundamentalfrequency of the oscillationsbeing received, underno circumstances willa clear tone be produced if the damping of the received oscillations isnot exceptionally weak, because it is very unlikely that during a seriesof undulations of the received energy a sufficient interference effectwill be produced to effect an impulse on the telephone diaphragm.Therefore, in this case itis of particular advantage to give theoscillations produced at the receiver a frequency that is higher byalmost a multiple than the oscillations received, because then thepossibility will be greater that one or a plurality of completevibrations will be-produced dur ing the dying out of the series ofundulations of the damped sender. In this manner, the telephonediaphragm will be actuated to give a clear sound, whereas in the othercase only irregular noises are perceptible.

Having described my invention what I claim is:

1. A method of receiving electrical oscillations which includesheterodyning the received energy by current, the frequency of whichdiffers by an audio frequency from a multiple of the fundamentalfrequency or the received energy.

2. A method of receiving'electrical oscillations which includesheterodyning the received energy by current, the frequency of whichdiffers by an audio frequency from a frequency which bears with thefundamental frequency of the received energy an integral ratio in whicheither the fundamental frequency or the last-named frequency may berepresented by unity.

8. A method of receiving electrical oscillations which includeshetcrodyning the received energy by current the frequency of whichapproaches more nearly to a multiple of the fundamental frequency of thereceived energy than to the fundamental frequency.

4. A method of receiving electrical oscillations which consists ingenerating an electric current at the receiver, producing by combinationof the received energy and said locally generated current a current, thefrequency of which is equal to the difference between the frequency ofthe locally generated current and a multiple of the fundamentalfrequency of the received energy, and utilizing said second-mentionedcurrent to actuate an indicator.

In testimony whereof I affix the signature.

ALEXANDER MEISSNE-R-

